Open Source Apps: eBook Reader

Want to read an e-book, but don't have a Nook, Kindle or iPad? This ebook reader supports multiple file formats and works on netbooks and Linux-based PDAs, as well as desktops. Operating System: Linux, Windows, BSD

With tens of thousands of downloads every year, dashCommerce is a very popular e-commerce engine. It offers a drop-in provider model for payment, shipping, tax and coupon providers; unlimited products; single-page checkout and more. Operating System: Windows

Based on osCommerce (see below), Digistore offers a full list of e-commerce features and requires no coding knowledge to set up and manage. Customization and consulting are available from the Digistore team, and the site also includes links to third-party vendors who offer hosted solutions. Operating System: Windows, Linux, OS X

This WordPress plug-in offers good, basic e-commerce features, but lacks some of the more advanced features in other e-commerce solutions. It does integrate with most payment processing systems. Operating System: OS Independent

As the name implies, this project offers a simple shopping cart engine that can be incorporated into more complex sites. It's based on PHP and MySQL, and it integrates with Google Analytics. Other features include an inventory control system, support ticket system, automatic payment notifications, search-friendly URLs and more. Operating System: Windows, Linux, OS X

Interchange has been around since 1995, and it supports a wide range of uses, including sales, content management, customer service, reporting and analysis, personalization, B2B, parts re-ordering, auctions, supply chain management, project management, online collaboration and even an MP3 jukebox. Professional support is available from a variety of third-party partners. Operating system: Linux, OS X

This eCommerce platform is designed to integrate with the JALLInOne ERP/CRM suite. Key features include fast search, catalog browsing, support for promotions and more. Operating System: Windows, Linux, OS X

Acquired by eBay earlier this year, Magento boasts more than 100,000 users, including OfficeMax, Harbor Freight Tools, K-Swiss and The North Face. It's available in three different editions—free community and paid professional and enterprise—as well as a hosted SMB solution called Magento Go. Operating System: Windows, Linux, OS X

One of the few .NET-based open source e-commerce options, nopCommerce is highly customizable with a pluggable architecture. It was designed to be search-engine-friendly and gets high marks for usability. Operating System: Windows

Nominated for a 2011 Packt Publishing award, OpenCart offers a long list of features and user-friendly operation. Commercial support is available from a variety of international third-party partners. Operating system: Windows, Linux, OS X

Aimed at manufacturers, distributors and rental companies, Order Portal is best for established companies that are looking to add an online presence. It also integrates with a larger Web Business Suite available from the same company. Operating System: Linux

This French project offers a "powerful and extensible" e-commerce solution. Check out the website for a helpful demo of Plici in action. Be warned that much of the documentation is in French, but English translations are available. Operating System: Windows, Linux

Django-based Satchmo calls itself "the webshop for perfectionists with deadlines." The site offers links to more than 100 stores created with the software, so you can see it in action for yourself. Operating System: Linux, OS X

A German project, Self Commerce is based on xt:Commerce (see above) and the Smarty template engine. Much of the website documentation is in German, but English versions of the software are available. Operating System: Windows, Linux, OS X

This very lightweight (under 20kb) JavaScript-based shopping cart offers very fast setup and doesn't require a separate database. However, in order to use it, you will need to know HTML. Operating System: OS Independent

This newer e-commerce platform calls itself "the world's most flexible." In addition to the free download, it's also available as a Rackspace-powered SaaS solution, and the site also offers discounts and easy sign-up for payment processing. Operating System: OS Independent

This add-on for the Joomla CMS offers advanced features like encryption, flexible tax models, shipping address management, multiple currencies and languages and more. The site has a demo and a number of links to live shops that use its shopping cart engine. Operating System: Winodws, Linux, OS X

Downloaded more than 1.3 million times, WordPress's eCommerce plug-in is a tried and true way to add e-commerce capabilities to your blog. Support, additional themes and other features and services are available for a fee. Operating System: OS Independent

Downloaded more than 400,000 times, X-Cart is 100% PCI-DSS compatible, SEO-friendly, and it supports many payment processers and shipping carriers. In addition to the free community version, it also comes in paid Pro and Gold editions, with additional modules and services available for sale as well. Operating System: Windows, Linux, OS X

Smarty-based xt:Commerce is a mature, German e-commerce solution with an English version available. In addition to the free community version, it also comes in premium supported versions with prices in euros. Operating System: Windows, Linux, OS X

Designed by "a group of like-minded shop owners, programmers, designers, and consultants," Zen Cart puts the emphasis on ease of use. Key features include a newsletter manager, support for coupons and gift certificates, XHTML templates, multiple payment and shipping methods and more. Operating System: OS Independent

This fork of Zen Cart (see below) offers features like unlimited products and categories, multi-currency and multi-language support, extensibility and simple PHP-based templates. Commercial support is available through Mixed Matter. Operating System: OS Independent

Open Source Apps: Educational Testing

If you're worried about your students cheating during a test, this app locks down the browser. While it's activated, it runs in fullscreen mode and prevents students from access other apps, the Internet, shortcuts, etc. Operating System: Windows

With iTest, teachers can easily give students different versions of the same test because all questions can be drawn at random from a database. The website includes a large library of screenshots that show exactly how the software works. Operating System: Windows, Linux, OS X.

Claiming to be "the most commonly used free CBA software in the world," this Web-based testing program greatly simplifies the process of creating, administering and grading tests. It's free for non-commercial use, or you can purchase a commercial license that includes support. Operating System: OS Independent

Open Source Apps: Elementary Education

For pre-school to kindergarten aged children, ChildsPlay includes 14 simple games, most of which teach numbers, letters, etc. It also includes some "just for fun" games like versions of Pacman and Pong. Operating System: Windows, Linux, OS X

Designed for children up to age 10, GCompris includes 100 separate games and educational programs. For example, it includes geography, math, reading, and science games, as well as chess, memory, connect 4 and Sudoku. Operating System: Windows, Linux

Because you're never too young for open source, KLettres teaches preschoolers to identify letters and their sounds. It also includes a "grown-ups" mode that aims to teach adults the basic building blocks of 25 different languages. (Note that in order to use KLettres on Windows, you'll have to download KDE for Windows.) Operating System: Windows, Linux

If you’re the kind of parent who believes children are never too young to learn how to code, check out this development environment for the grade-school crowd. Using only the mouse, Little Wizard users learn about programming concepts like variables, expressions, loops, conditions, and logical blocks. Operating System: Windows

In this game, players solve arithmetic problems in order to prevent meteors from smashing Tux the penguin in his igloo. It offers a variety of types of problems for students with different skill levels. Operating System: Windows, Linux, OS X.

Open Source Apps: E-mail

Often called "the Outlook of Linux," Evolution offers e-mail, calendar and other capabilities from an interface that looks a lot like the Microsoft product. Other notable features include built-in spam filtering, advanced search capabilities, encryption support, and iCalendar support. Operating System: Linux

Made by Mozilla, the organization behind Firefox, Thunderbird is a tabbed, searchable e-mail client with an emphasis on customization capabilities. If you want an integrated calendar, you'll also need to download the Lightning add-on. Operating System: Windows, Linux, OS X

Zmail describes itself as a "fake e-mail program" that allows you to send e-mail from anyone to anyone. It's useful for testing mail servers or for sending e-mail without using your regular account. Operating System: OS Independent

Open Source Apps: E-mail Marketing

OpenEMM boasts that it offers 95 percent of the features of commercial e-mail marketing software, as well as some features the commercial products don't have. A hosted version is available through Agnitas. Operating System: Windows, Linux.

The "world's most popular open source email campaign manager" has launched a beta of its new hosted service. For now, users can send up to 300 messages per month (50 per day) for free through the hosted service. The full-featured paid version is slated to launch before the end of the year. Operating System: OS Independent.

Open Source Apps: Encryption

Used by more than 2.2 million people, AxCrypt calls itself the "leading open source file encryption software for Windows." It integrates seamlessly into the Windows File Explorer—just right-click to encrypt a file and protect it with a password, or double-click to decrypt. Operating System: Windows

This encryption tool is extremely lightweight (44KB) and fast, and you don't have to install it to use it. However, that speed and light weight is due to the fact that it doesn't have a GUI, so you'll need to be comfortable working from the command line ot use it. Operating System: Windows

Short for "free on the fly encryption," this tool creates encrypted virtual disks on your hard drive. It can run from a thumb drive, and it supports multiple hash and encryption algorithms. Operating System: Windows

GnuPG (aka GPG) allows Linux users to sign and encrypt their data or digital communications. This is a command line tool, but several front ends (including some we've featured on this list) are available. Operating System: Linux

As you can tell by the name, this version of GPG encrypts files and e-mail on Windows systems. This version is a little bit easier for the less technically inclined to use than some of the others. Operating System: Windows

This replacement for the Unix crypt allows developers to add a wide range of encryption functions to their code, even if they don't know a lot about cryptography. The Web site contains a list of supported algorithms that are included in the Libmcrypt library. Operating System: Windows, Linux, Unix

This digital signature project supports all Open SC cards and aims to be the first single app that can be used with cards from multiple countries. Open Signature originally focused on cards used in Italy but has branched out. Operating System: Windows, Linux, Unix

As you might guess from the name, this app lets you secure your folders. It gives you the option of hiding, locking, and/or encrypting folders to keep them safe from prying eyes. Operating System: Windows, Linux.

Downloaded nearly twenty million times, this popular encryption tool can protect an entire drive or an entire partition of a drive. And its parallelization and pipelining techniques mean you won't notice any performance delays on your encrypted drive(s). Operating System: Windows

Open Source Apps: Enterprise Resource Planning (ERP)

In addition to e-commerce and ERP functionality, the Apache Open for Business Suite includes CRM, supply chain management, enterprise asset management, point-of-sale and other capabilities. It offers small businesses advanced e-commerce features along with excellent flexibility. Operating System: OS Independent

This fork of WebERP (see below) offers flexibility and the ability to integrate with many other types of software. Small businesses can use it to manage sales quotes, orders, invoicing, receivables, inventory, purchases, payables, banking, and general ledger accounting. Operating System: OS Independent

In addition to ERP functionality, this app adds CRM, MRP, SCM, accounting, HR and PDM capabilities. It comes in a version for mobile phones, and it also available in commercially supported and SaaS versions. Operating System: Linux

With more than 2 million downloads, Openbravo boasts that it is the "world’s leading Web-based open source ERP solution." In addition to the free community version, it also comes in paid basic and professional editions that can be deployed on-site or in the cloud. Operating System: OS Independent

Used by more than 1,000 companies around the world, project-open (or "po") combines ERP and project management functionality. The core modules are free, but additional modules and support require a fee. Operating System: Windows, Linux

xTuple's ERP suite includes accounting, sales, CRM, purchasing, product definition, inventory and distribution, light manufacturing and reporting capabilities. The Postbooks edition is available with either an open source or a commercial license, and the Standard, Project, Manufacturing or Enterprise editions are available only with a commercial license. It's also available in the cloud, and information about other related services is also on the website. Operating System: Windows, Linux, Unix, OS X

Another Web-based application, SQL-Ledger features double-entry accounting and ERP features and, as you might guess, stores data in a SQL database server. Paid support is available at a variety of price points. Operating System: Windows, Linux, OS X

This popular app is downloaded an average of 5,000 times per month. While it can be used by any type of business, webERP is particularly well suited to the needs of wholesalers, distributors and manufacturing companies. Commercial support and hosting are available through third-party organizations. Operating System: OS Independent